内外科护理:心血管与呼吸
方法
- 说出问题所在:泵衰竭、动脉阻塞、节律、血栓、气道狭窄、感染或设备问题。
- 先检查危险征象:低氧、低血压、胸痛、新出现的意识模糊、冰冷无脉搏的肢体。
- 让氧疗与患者相匹配:大多数人为 94–98%,有 CO₂ 潴留风险者为 88–92%。
- 把每种药物与其检测和风险联系起来:华法林与 INR,肝素与 aPTT 和血小板,利尿剂与血钾。
- 选择安全的第一步措施,然后升级处理并重新评估。
公式表、每个专题的关键方法步骤和 16 道练习题,完整解答附在最后。
Why must inspired air be humidified for a patient with a tracheostomy?
A patient with severe sepsis becomes increasingly breathless over 24 hours. SpO₂ stays low despite high-flow oxygen, and the chest X-ray shows bilateral infiltrates. The heart function is normal. Which condition is most likely?
一名高血压难以控制、血钾持续偏低的患者,未使用利尿剂。应考虑哪种疾病?
A patient with known back pain says they now cannot feel the skin between their legs and have not passed urine for 12 hours. What should happen?
Why should metoclopramide not be used for nausea in mechanical bowel obstruction?
A patient asks whether to take their usual bisoprolol on the morning of surgery. What is the usual guidance?
An arterial blood gas shows a low pH, a high PaCO2 and a normal bicarbonate. What does this show?
A patient with stress incontinence is taught self-care. Which statement shows a need for further teaching?
A 55-year-old has a positive fecal immunochemical test (FIT) during routine screening. What is the usual next step?
一名患者在大量呕血 30 分钟后到达。心率 125 次/分,但首次血红蛋白为 13.0 g/dL(130 g/L)。为什么血红蛋白具有误导性?
某练习动脉血气显示 pH 7.37,PaCO₂ 59 mmHg (7.9 kPa),HCO₃⁻ 33 mmol/L。原发性紊乱是呼吸性酸中毒。代偿到什么程度?点选你的答案。
练习数值:Na⁺ 136,Cl⁻ 106,HCO₃⁻ 15 mmol/L,白蛋白 35 g/L。求经白蛋白校正的阴离子间隙 AGc = AG + 0.25·(40 − 白蛋白)。
解读这条 II 导联心律条带。这是什么节律?点击你的答案。
依次按五个步骤解读这条 II 导联心电图:心率、节律、P 波、PR 间期、QRS 时限。你在哪一步发现第一个异常?点击它。
哪项发现是非预期的,需要及时跟进?
A victim heavily contaminated with an industrial chemical arrives at the emergency department with stable vital signs. What should happen first?
答案: D · The nose and upper airway, which warm and moisten air, are bypassed
The tracheostomy bypasses the nose, mouth and pharynx, which warm, filter and humidify air. Without humidification, secretions become thick and can block the tube. Heat and moisture exchangers, humidified oxygen and nebulised saline are used.
答案: D · Acute respiratory distress syndrome
ARDS is acute, non-cardiogenic pulmonary oedema caused by widespread inflammation, triggered by sepsis, pneumonia, trauma or pancreatitis. It causes severe hypoxaemia that responds poorly to oxygen, with bilateral infiltrates not explained by heart failure. Treatment includes lung-protective ventilation and often prone positioning.
答案: A · 原发性醛固酮增多症(Conn 综合征)
醛固酮过多导致钠水潴留(高血压)和钾丢失(低钾血症)。原发性醛固酮增多症是高血压常见的继发原因,通过醛固酮/肾素比值筛查。Addison 病的表现则相反。
答案: B · Urgent MRI and referral to the spinal surgeons
Saddle anaesthesia with urinary retention suggests cauda equina syndrome. Delay can lead to permanent bladder, bowel and sexual dysfunction. The patient needs an emergency MRI and surgical decompression if confirmed.
答案: B · It increases gut movement against the blockage
Metoclopramide stimulates gastric and intestinal motility, which can worsen pain and risk perforation in complete mechanical obstruction. Other antiemetics are chosen.
答案: A · Usually continue it with a sip of water, unless told otherwise
Beta-blockers are usually continued around surgery because sudden withdrawal can cause rebound tachycardia and ischaemia. The patient follows the specific instructions from the preoperative assessment.
答案: D · Respiratory acidosis
A raised PaCO2 with a low pH means the lungs are not removing enough CO2, for example from hypoventilation. A normal bicarbonate suggests it is acute.
答案: A · "I'll drink as little as possible so I don't leak."
Restricting fluids concentrates urine, irritates the bladder and risks dehydration and infection. Pelvic floor exercises, weight loss and reducing caffeine are recommended measures.
答案: C · Referral for colonoscopy
A positive FIT means hidden blood in the stool, which may come from a polyp, cancer or other lesion, so a colonoscopy is needed to find the source. A positive screening test is never ignored, even without symptoms.核对依据: Fecal Occult Blood Test (FOBT) · MedlinePlus (NIH) (2024)
答案: D · 丢失的是全血,所以浓度数小时后才会下降
出血早期,红细胞和血浆一起丢失,因此浓度起初保持正常。在最初几小时,心率和血压是判断失血更好的指标。
答案: 完全代偿
解读血气(ROME):先看 pH:低于 7.35 为酸血症,高于 7.45 为碱血症。然后找出能解释它的指标。PaCO₂(正常 35–45 mmHg,4.7–6.0 kPa)是呼吸方面的指标,在呼吸性紊乱中与 pH 反向(Opposite)变化;HCO₃⁻(正常 22–26 mmol/L)是代谢方面的指标,与 pH 同向变化(Respiratory Opposite, Metabolic Equal,即呼吸性相反,代谢性相同)。另一个指标显示代偿情况:正常表示未代偿;沿着使 pH 回升的方向异常、而 pH 仍然异常,表示部分代偿;pH 正常而两个指标都异常,表示完全代偿。各实验室的范围略有差异;这些是练习用数值。
答案: AGc = 16.25 mmol/L
预期代偿:代谢性酸中毒时,温特公式预测 PaCO₂ = 1.5·HCO₃⁻ + 8 ± 2 mmHg;实测值高于该范围提示合并呼吸性酸中毒,低于该范围提示合并呼吸性碱中毒。阴离子间隙 AG = Na⁺ − (Cl⁻ + HCO₃⁻),正常约为 8–12 mmol/L,用于区分高阴离子间隙与正常阴离子间隙代谢性酸中毒;低白蛋白会掩盖升高的间隙(白蛋白低于 4.0 的部分,每 g/dL 加 2.5)。Δ 比值 (AG − 12)/(24 − HCO₃⁻) 约在 0.8 到 2 之间符合单纯高间隙酸中毒(有些教材用 1 代替 0.8),低于此范围提示合并正常间隙酸中毒,高于 2 提示合并代谢性碱中毒。
校正后高于约 12:阴离子间隙升高。
答案: 室上性心动过速(SVT)
节律标准(II 导联):窦性心律每个 QRS 之前都有直立的 P 波,PR 恒定为 0.12–0.20 s,QRS 狭窄:60–100 次/分为正常窦性心律,低于 60 为窦性心动过缓,高于 100 为窦性心动过速。心房颤动:无 P 波,基线呈颤动,R–R 绝对不规则。心房扑动:约 250–350 次/分的锯齿状扑动波,伴固定的传导比例,如 2:1 或 4:1。一度房室传导阻滞:窦性心律,PR 恒定且大于 0.20 s。交界性心律:窄 QRS,40–60 次/分,P 波缺失或倒置(PR 低于 0.12 s,或 P 波在 QRS 之后)。室性早搏(PVC)是提前出现的宽大(0.12 s 或以上)、形态怪异的 QRS,没有 P 波,T 波方向相反,通常有完全性代偿间歇;二联律是指每隔一个搏动就有一个室性早搏。 窄 QRS 心动过速与停顿:室上性心动过速(SVT)是规则的心动过速,约 150–250 次/分钟,QRS 波群较窄;P 波通常看不到,因为它们隐藏在 QRS 波群或 T 波中。成人静息时的窦性心动过速通常低于约 150 次/分钟,且每个 QRS 前都有可见的 P 波;伴 2:1 传导的心房扑动常在约 150 次/分钟,并显示锯齿波。窦性停搏是指窦房结暂时停止发放冲动:出现既无 P 波也无 QRS 的停顿,其长度不是 P–P 周期的整数倍(恰好两个或三个周期的停顿则提示窦房传导阻滞)。
答案: 折旧率
每条心电图的五个步骤:1. 心率(300 法或 1500 法;若不规则则用 6 秒法);2. 节律:R–R 间期是否相等;3. P 波:是否存在、在 II 导联直立、每个 QRS 之前各有一个且形态一致;4. PR 间期:0.12–0.20 s 且恒定;5. QRS 时限:低于 0.12 s。五个步骤做完之后才命名节律。正常窦性心律五项全部符合:60–100 次/分,规则,每个 QRS 之前有直立 P 波,PR 0.12–0.20 s,QRS 低于 0.12 s。
答案: D · 一名使用肝素输注的患者出现新的黑色柏油样大便
黑色柏油样大便(黑便)提示上消化道出血,是抗凝治疗的危险并发症。腹腔镜手术后因使用的气体而出现肩痛很常见,COPD 的桶状胸和肝硬化稳定的黄疸是预期的。
答案: C · Decontamination before the victim enters the treatment area
A stable, contaminated victim is decontaminated before entering the department, to protect staff, other patients and the victim. Life-saving care may come first only if the victim is unstable.
ExamProblems · examproblems.com/courses/medical-surgical-nursing